Isometric piping template rule



Nov. 4, 1958 w. A. VERRETT ISOMETRIC PIPING TEMPLATE RULE Filed Sept. 25, 1956 V mm M 6 w w Ill! Inn -2t United States This invention relates to a drafting instrument having for its object the provision of a template rule designed to facilitate the making of drawings of piping layouts or systems.

Throughout the industrial world there is the necessity of making countless numbers of piping drawings by engineers, draftsmen, craftsmen, and others connected with practically every phase of industry, and while there are time-saving aids for this purpose, there are none within applicants knowledge so versatile in their adaptation to the requirements of the almost infiinite variations of piping layouts, as to promote standardization in the drawings of such piping systems.

Another object of the invention is to provide a template rule for the purpose of simplifying, speeding up, and particularly standardizing the making of isometric piping drawings.

Still another object of the invention is to provide a template rule having a base plate adapted to be guided along a T-square or to be slidably attached to a drafting machine, having an arm extending perpendicularly from said base plate at an intermediate point, and having arms at each side of said perpendicular arm defining with the adjacent edge of said base plate angles of 30, and with said perpendicular arm angles of 60, said rule by virtue of the'symmetrical relation of said lateral arms with respect to the center line of said perpendicular arm, being adapted to-draw isometrically the piping on both sides of a vertical datum, without the necessity of turning the rule over.

A further object of the invention is to provide a template rule of the type described, in which the radiating arms have arcuate edges both at their bases and free ends for drawing the connecting arcs between lines that represent those parts of the piping system that lie in vertical planes, and having a cutout located symmetrically with respect to both sides of the center line through the per pendiculararm, said cutout having arcuate edges for drawing the connecting arcs of lines that represent those parts of the piping system which lie in horizontal planes.

A further object of the invention is to provide the radiat ing arms with similar series of cutouts along their longitudinal center lines, the bounding edges of which outline the conventional symbols of fittings, and which cutouts may be selectively used fordrawing fittings along the depicted lines of piping.

Other objects of the invention will appear as the following description of a practical embodiment thereof proceeds.

in the drawing which accompanies and forms a part of the following specification, and in the figures of which the same reference characters have been used to denote identical parts:

Figure 1 is a plan view of a practical embodiment of my piping isometric template rule;

Figure 2 is a cross-section taken along the line 2-2 of Figure 1;

atent ice Figure 3 is an isometric diagram of piping illustrating the use of the rule.

It is, of course, well known that an isometric drawing distinguishes from a perspective drawing, in that there is no vanishing point, so that lines which are parallel and of equal length in reality remain parallel and of equal length in the isometric showing, permitting true proportional measurements to be taken directly from the drawing. It is more or less conventional to arrange the figure to be drawn with the foremost angle symmetrical with respect to a horizontal datum line, the sides of the foremost angle making with said datum line angles of 30. This arrangement makes all other angles between lines which are rectangularly related multiples of 30, that is, either 60 or In the piping diagram of Figure 3, the pipes 1, 2, 3 and 4 lie in a common horizontal plane, the forward angle a and the opposite angle a being 120, and the alternate angles b, only one of which is shown, being 60. The pipes 2 and 5 are in a vertical plane, joining at an angle 0 of 120, and pipes 4 and 6 are in a vertical plane, oppositely directed with respect to the plane of pipes 2 and 5, joining at an angle d of 60.

In the piping diagram, angularly related pipes are joined by connecting arcs except where branches debouch from fittings. In an isometric drawing, all lines which are vertical in reality are vertical, and all lines which are horizontal in reality in the drawing, either actually or if produced, make angles of 30 with the horizontal datum line, the latter representing a line in a vertical plane perpendicular to the line of sight of the observer.

The isometric template rule, as shown in Figures 1 and 2, is designed to produce piping diagrams or layouts having the characteristics of the diagram above described, and which is used for purpose of illustration. The rule is preferably made of clear plastic, comprising a base plate 10, having a lower straight edge 11, adapted to slide upon the horizontally held edges of a T-square, or if a drafting machine is available, adapted to be connected thereto by the connection 12. Said connection, as shown, represents a patented device disclosed in patent to Vard B. Wallace, No. 2,192,422, granted March 5, 1940, and which need not be further described in this specification.

A vertical arm 13 extends perpendicularly at an intermediate point from the upper side of the base plate, and lateral arms 14 and 15 radiate from the foot of the perpendicular arm, one on each side and symmetrical with respect to the center line 16 of the perpendicular arm, which is marked thereupon. are marked with center lines 17 and 18. All three of the radiating arms are preferably of uniform width and have lateral straight edges 19 and 20 on both sides, parallel to the respective center lines. The edges 19 and 20 are used in drawing vertical lines, which are invariably employed to depict piping which is vertical in actuality. The

edges 21 and 22, and 23 and 24 of the respective inclined arms .are used for drawing lines which represent horizontal piping in the actual piping system. The inclined arms 14 and 15 converge at angles of 30 with respect to the upper straight edge 25 of the base plate, and at angles of 60 with the perpendicular arm. The sides of the several angles defined between the threeradiating arms and between the inclined arms and base plate are connected by arcuate edges 26, 27, 28 and 29, adjacent their apical ends, which arcuate edges are used as templates in drawing pipe bends connecting the straight reaches of pipe. Since there is no necessity for a 30 bend in the isometric drawing, all actual right angles being depicted by 60 or 120 angles, the arcuate edges 28 and 29 which close the 30 angles between the upper edge 25 of the base plate and the lower edges 21 and 24 The arms 14 and 15 also of the inclined arms, each has one extremity aligned with said lower edges and the other extremity perpendicular to the edge 25, the two extremities defining an angle of 120, useful in drawing bends such as that which closes the angle in Figure 3.

The base plate at the foot of the perpendicular arm ,13 is provided with a cutout 30 arranged symmetrically with respect to the center line 16 of the perpendicular arm, the peripheral edges of said cutout defining opposite pairs of arcs 31 and 32, the arcs of each pair being similar, the arcs 31 having their extremities divergent at an angle of 120, while the extremities of the arcs 32 diverge at an angle of 60. One of the arcs 31, as shown, has its extremities in alignment with the upper straight edges 22 and 23 of the inclined arms, and is useful in closing the angle of 120 between said upper edges, in drawing for example, the pipes 1 and and the bend a in Figure 3.

The lateral arms 14 and terminate in straight edges 33 and 34 perpendicular to the base edge 11, and therefore making respective angles of 60 to 120 with the upper and lower straight edges of said lateral arms. These angles are closed by arcs 35 and 36, whose extremities diverge at angles of 60 and 120, respectively.

At the upper end of the perpendicular arm 16 there are three arcuate edges 37, 38 and 39 which each measures an angle of 120, and which like all of the other 60 and 120 arcs provided by the rule, may be selectively employed according to the dictates of convenience. Since all of the straight and arcuate edges on one side of the center line of the rule are repeated on the other side, it is never necessary to turn the rule over, much time being saved by this avoidance.

Each of theradiating arms is provided with a series of cutouts 40, extending along the respective center lines, and being intersected thereby. These cutouts are shaped to have the isometric form of various fittings employed in connection with piping systems. For example, 40a is a coupling Welded laterally to a line; 40b is a pipe cap; 40a is a concentric reducer; 40d is a flange; and 40a, a valve. The center lines are preferably inscribed on the under side of the rule for lining up the center lines of the cutouts with respect to the underlying drawing. In order to simplify the isometric drawings, the directions -N, S, E and W, Up, and Down are inscribed on the rule. The base plate 10 is provided with the cutout 41, forming a template for drawing an identifying box in which to place piece marks of individual pieces shown in the isometric drawing.

It is the general purpose of the invention to greatly speed up, simplify and standardize the making of piping drawings throughout industries which are concerned with drawings of this type. The rule will eliminate the necessity for employing cross-hatched guide paper which are sometimes used for isometric drawings. Continually turning a 3060 triangle will no longer be necessary. Free handing can be eliminated, so that every drawing will become standardized, as templates promote uniformity.

It will be understood by those skilled in the art that the Specific construction and arrangement of cutouts, as shown and described, are by way of illustration and not to be construed as necessarily limiting the scope of the invention.

What I claim is: v

1. Isometric piping template rule. comprisinga transparent integral sheet member shaped to provide a base plate having a lower straight edge adapted to engage a T-square and an upper straight edge parallel thereto and a trio of arms of uniform width extending from the upper edge of said base plate having their medial longitudinal lines radiating from a common point and being in part inscribed upon said arms, one of said arms being perpendicular to said base plate and the others divergent therefrom on opposite side at equal angles, the opposite side edges of said arms constituting straight edges which extend continuously to the outer ends of the arms,

the ends of said divergent arms being formed with straight.

edges parallel to said perpendicular arm whereby the upper sides of said divergent arms make angles with said end straight edges equal to the angles between said upper sides and the sides of said perpendicular arm, the apical ends of all said angles being arcuately closed.

2, Isometric piping template rule as claimedin claim 1, the edge of the free end of said perpendicular arm being triangular, having a medial salient apex angle symmetrical with respect to the medial longitudinal'line of .said perpendicular arm, and qual to the angle between the lower side of either of said divergent arms and said end straight edge, the angles of the edge of the free end of said perpendicular arm being arcuately closed.

3. Insometric piping template rule comprising a transparent integral sheet member shaped to provide a base plate having a lower straight edge adapted to engage a T-square and an upper straight edge parallel thereto and a trio of arms of uniform width extending from the upper edge of said base plate having their medial longitudinal lines radiating from a common point, one of said arms being perpendicular to said base plate and the others divergent therefrom on opposite sides at equal angles, the opposite side edges of said arms constituting straight edges, which extend continuously to the outer ends of the arms, the ends of said divergent arms being formed with straight edges parallel to said perpendicular arm whereby the upper sides of said divergent arms make angles with said end straight edges equal to the angles between said upper sides and the sides of said perpendicular arm, the apical ends of all said angles being arcuately closed.

4. Isometric piping template rule as claimed in claim 3, each of said divergent arms being provided with a series of cut-outs along their inscribed center lines, said cutouts forming templates having peripheral edges defining the isometric representations of various pipe fittings.

References Cited in the file of this patent UNITED STATES PATENTS 262,137 Silliman Aug. 1, 1882 777,770 Barnes -Dec. 20, 1904 2,371,485 Waldman Mar. 13, 1945 2,610,407 McQuaid Sept. .16, 1952 2,734,274 Sams Feb. ,14, 1956 FOREIGN PATENTS 676,698 Germany June 9, 19 39 

